Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a well that penetrates a hydrocarbon-bearing formation. Once a wellbore is drilled, various forms of well completion components may be installed to control and enhance the efficiency of producing the various fluids from the reservoir. One piece of equipment that may be installed is an electric submersible pump (ESP). Typically ESPs have a limited run-life, and as such, it may be necessary to change them out many times during the life of a well. ESPs may be deployed in both subsea and non-subsea completions. To function, ESPs must be provided with electric power, and the connection from the supply source is often made after the ESP is deployed (i.e., downhole).
The search for oil reserves is extending ever deeper into remote regions of the earth. In the Gulf of Mexico, for instance, the lower tertiary formations such as the Wilcox of the Paleocene era pose significant challenges due to complex formations and low permeability. The completions for those wells may not be commercially viable without ESPs. However, those reservoirs initially have high operational pressures in the range of 13,500 pounds per square inch (psi), which require the pump system and wellheads be rated anywhere from 15,000 psi to 20,000 psi for operational pressure. To power the associated pumps, a subsea tree may need to have a wet-mateable connection system capable of providing two megawatts (MW) of power through the tree system. There may also be large pressure differentials across the tree boundaries that must be handled over the lifetime (e.g., ten years) of the system/tree. In addition to being able to withstand high differential pressures, the penetration system (i.e., connector assembly) must be able to handle the effects of high temperature due to intrinsic bottom hole temperatures, heating from fluid pumping, and joule heating (I2R) from electrical current.
Traditionally, subsea ESP wet connection systems are designed for 5000 psi subsea tree applications, and the insulation systems on the contact pins for those connectors are formed using thermoplastic insulators, formed through injection molding, using materials such as polyether ether ketone (PEEK). PEEK insulated pins can, over time, suffer from plastic creep under high pressure and high temperature conditions.